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John's big thing in life is to do an internet search on any current subject,
he then regurgitates it so he can appear to have something to add to the discussion. "W8JI" wrote in message oups.com... Aw comen on now John. Every single link coupled transformer from the 1900's to today works on the principle, as do link coupled tuners or matching systems. |
Ian White wrote,
"Sorry, but it all seems to come down to the definitions of "current balun" and "transmission line transformer" that one chooses to adopt. Rather than referencing those definitions, please can you quote them here, in full?" I agree. In fact, in thinking about it, I realized that I'm more likely to use the terms "choke balun" and "transformer balun" than current and voltage balun. Roy's analysis of (1:1 current/choke) baluns, available at http://eznec.com/misc/ibalun.txt, may be interesting reading for lurkers here who may be confused by this thread. Cheers, Tom |
W8JI wrote:
Making up a new definition is not the same as producing a new or novel invention. This is almost like the new invention call Fractal antennas or E-H antennas that don't use "old" technology! This thread has got me wondering if "Ruthroff" balun is the same as "voltage" balun and if "Guanella" balun is the same as "current" balun, as was explained to me once by a balun guru. -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
Tom stands up and tells the world what he thinks We know who Tom is, and of
his many accomplishments. He, unlike you, signs his name to his statements. You have obviously failed to make a dent in the technical arena, or like Tom you would sign a cogent rebuttal as opposed to your school yard antics. If you can't compete on a technical level, sit back down in the peanut gallery and learn grasshopper. "WdntULik2no" wrote in message news:inmngeygcwrq14x.280620051612@kirk... w8ji please tell me some damn fool has not put you in a position to influence people you are an idiot WdntULik2no |
I just happened upon an App. note written by Philips
Semiconductors (ECO6907) titled "Design of HF wideband power transformers" which states for both 4:1 and 9:1 transmission line transformers that they CAN be wound on a single core if desired for certain conditions (see sections 6.3, 6.4 and 6.6). http://www.semiconductors.philips.co...es/ECO6907.pdf 73, Larry, W0QE |
"Larry Benko" wrote in message ... I just happened upon an App. note written by Philips Semiconductors (ECO6907) titled "Design of HF wideband power transformers" which states for both 4:1 and 9:1 transmission line transformers that they CAN be wound on a single core if desired for certain conditions (see sections 6.3, 6.4 and 6.6). http://www.semiconductors.philips.co...es/ECO6907.pdf 73, Larry, W0QE And, that comes in TWO parts. ECO6907 and ECO 7213. BOTH wonderful resources, and both apply to the discussion here. (They DO call them "conventional transformers" and not Baluns.) W4ZCB |
just happened upon an App. note written by Philips
Semiconductors (ECO6907) titled "Design of HF wideband power transformers" which states for both 4:1 and 9:1 transmission line transformers that they CAN be wound on a single core if desired for certain conditions (see sections 6.3, 6.4 and 6.6). http://www.semiconductors.phil=ADips...i=ADcationnot= ..=2E. 73, Larry, W0QE Hi Larry, Don't fall into the trap of swallowing out of context quotes by Trask. That's an old tired game, and it only results in everyone chasing their tails to argue about nothing. 1=2E) I very specifically excluded primary-secondary type transformers from the single core current balun statement. 2=2E) I very specifically was speaking of a dual transmission line 1:1 balun Sevik described using two 1:1 transmission line current baluns on one core. If you can think of a way to build a transmission line balun that way that is a current balun, please let us all know. No one has been able to do it so far. Calling a primary-secondary transformer a "transmission line" does not count, so no "creative" ways to describe something following Lenz's laws rather than TEM mode is necessary. Everyone already knows a conventional primary secondary transformer will work. 73 Tom |
The article calls all of the devices transformers, not "conventional
transformers" including the phase inverter that is a TLT. |
"KD5NWA" wrote in message oups.com... The article calls all of the devices transformers, not "conventional transformers" including the phase inverter that is a TLT. Actually, if you'll take a read of part 2 of the application note ECO6907, (ECO7213, which I referenced) It specifically states that part 1 was devoted entirely to the design of *transmission line transformers*, which had the advantage of the widest possible bandwidth, but several disadvantages as well. Therefore, part 2 considers the possibility of applying a *conventional transformer* if those constraints were undesireable. Sheeeeeeeeesh! W4ZCB |
2. That it is not a true transmission line transformer, because your transmission-line windings are not being fed with opposite polarities across the *same* end? Ian, I wanted to give a more thorough reply to your question earlier, but at the time a spontaneous reply did not seem to be sufficient. So, I have put together an extensive tutorial on the subject of the theory, synthesis, and practical considerations in the design of transmission line transformers that is a result of over two decades of designing these things as a hands-on hardware designer: http://www.home.earthlink.net/~chris...LTTutorial.pdf Chris ,----------------------. High Performance Mixers and / What's all this \ Amplifiers for RF Communications / extinct stuff, anyhow? / \ _______,--------------' Chris Trask / N7ZWY _ |/ Principal Engineer oo\ Sonoran Radio Research (__)\ _ P.O. Box 25240 \ \ .' `. Tempe, Arizona 85285-5240 \ \ / \ \ '" \ IEEE Senior Member #40274515 . ( ) \ '-| )__| :. \ Email: | | | | \ '. http://www.home.earthlink.net/~christrask c__; c__; '-..'.__ Graphics by Loek Frederiks "Ian White GM3SEK" wrote in message ... Chris Trask wrote: It's not a matter of whether I disagree with him or not. It's a matter of him standing on a cybersoapbox and declaring to the world in numerous ways that such a thing cannot work and that only his analysis of how it can and cannot work is valid. He can't deny that he claimed that it was impossible, so now he has to prove that the solution cannot possibly work the way that he knows that it cannot work. Whatever. Please skip the personal rhetoric, and tell us how you respond to his two main technical points about your transformer: 1. That it is simply a 2:1 transformer with an isolated primary and secondary? 2. That it is not a true transmission line transformer, because your transmission-line windings are not being fed with opposite polarities across the *same* end? -- 73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB) http://www.ifwtech.co.uk/g3sek |
I think the basis of Chris' claims is that equal and opposite currents
flowing in two parallel or concentric conductors makes it a "transmission line". I can give examples where that isn't true. In any conventional transformer with a load across the secondary, the secondary current will flow opposite the primary current based on Lenz's law. It is magnetic field coupling from aprimary to a secondary that causes that effect. KD5WNA probably just didn't read the application note carefully, and missed that part 1 covers transmission line transformers and part 2 just transformers. Every peer reviewed textbook I have that deals with transmission lines states they transfer energy via TEM mode (transverse electromagnetic mode, not electric magnetic as the "tutorial" by Trask states). The key is all in the excitation and termination of the windings. There is a great deal of difference in how energy gets from one place to the other in the two systems. That's why bandwidth is restricted in a conventional transformer mode, and loss over wide bandwidths is generally higher in a transformer rather than a transmission line mode of coupling. The real title of Chris' tutorial should be "What I Think a Transmission Line Is", because that's all he really disagrees with me about. I think a transmission line conveys energy via TEM mode, he thinks it conveys energy through flux coupling. We simply have a disagreement of definitions. I was speaking very specifically about a balun Sevik described that would not provide a balanced current source. Chris has extracted certain sentences from a long exchange to prove some unimportant point about him being right and me being wrong, and totally skirted the issue of Sevik's design being flawed. The tragedy of this is some people will think Sevik's design is a good one, because if Chris is right about this one thing I must be wrong about everything I said regarding Sevik's not-too-good balun suggestion. 73 Tom |
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